The oral and buccal cavity has been used for administration of active substances in many years. This administration route has especially been attractive in order to avoid first pass metabolism or e.g. for dosage forms suitable for application under the tongue in order to obtain a fast uptake (e.g. sublingual administration of glyceryl nitrates for alleviating symptoms associated with angina pectoris).
However, improvements with respect to fast uptake and availability of an active substance are still needed; cf. the following in which nicotine is used as a non-limiting example of an active substance.